A cooling sensation agent that endows the skin, oral cavity, nose and throat of a person with a refresh feeling (refresh sensation) and cool feeling (cooling sensation), that is cooling sensation effect, is used in various products such as toothpastes, confectioneries such as chewing gums and candies, tobacco, cataplasms, bath agents and cosmetics. 1-Menthol has been known as a representative cooling sensation agent, however the cooling sensation effect thereof does not last so long. Therefore, studies of prolonging cooling action thereof have been conducted. Examples of compounds with long-lasting cooling action over a prolonged period developed include menthoxypropanediol which is glycerol ether of menthol, lactic ester of menthol, and ethylene glycol ether of menthol.
However, under influence of recent global warming, there has been a demand for cool processing of clothes and the like to make people feel more comfortable even in hot summer. Most cooling sensation agents are highly volatile and also highly water-soluble, as described above, and thus, the cool processing of clothes often resulted in decline of the action in a short period of time. For example, even if a cooling sensation agent is compounded with a detergent or a softener for example, the cooling sensation agent hardly remains on the clothing fiber after washing because of its water solubility and further, no cooling sensation agent remains after drying because of its high volatility.
Sustained-release cooling sensation agents utilizing a chemical change were developed to solve the problems described above. Examples of such agents developed include a chlorocarbonic ester or carbonic ester thereof as cooling sensation agent that contained in tobacco and releases menthol by its thermal decomposition on combustion of tobacco and thus, providing tobacco with refreshment when inhaled (see Patent Document 1 below), a carbonic esters that releases a fragrance component by decomposition thereof on the skin, thus elongating the diffusion period of a fragrance (see Patent Document 2 below), and an ortho ester that releases a fragrance when decomposed by perspiration on the skin (see Patent Document 3 below), and the like. In addition, there are many patents that utilize release of a fragrance molecule by decomposition of a fragrance precursor based on a chemical change or an enzyme reaction (see Patent Documents 4 to 7, Non-patent Document 1 below and others). However, these compounds still had problems such as significantly longer period needed for release of a fragrance compound in decomposition reaction after adhesion to cloth or skin and its lower strength, and thus, there being still many problems to be overcome.
Other studies on the method of providing clothes with cooling action using microcapsules and the like have been conducted, and many patent applications has been filed. Examples thereof include a fiber processing method of using microcapsules containing mint oil or 1-menthol (see Patent Document 8) and a fiber processing method of using a microcapsulated substance melting at a temperature not higher than the body temperature, so that the substance gives persons a cooling action reversibly by latent heat when in contact with skin (see Patent Document 9). However, in the former method, of course, processed fibers loses its action after release of the cooling sensation agent by breakdown of the microcapsules, and it is actually impossible to process the clothes similarly at home. In addition, because the stage of releasing the cooling sensation agent by breakdown of the microcapsules is the rate-determining step in this method, as same as chemical reaction, it is not currently at the technological level providing persons the cooling action immediately after wearing of the cloth. In addition, the latter method, which relies on phase transition between solid and liquid, cannot provide persons the cooling action in areas where it is so hot that the microcapsulated substance does not return to the solid phase after melting.    Patent Document 1: U.S. Pat. No. 3,312,226    Patent Document 2: JP-A No. 10-95752    Patent Document 3: WO 94/06441A    Patent Document 4: EP Patent No. 1077251A    Patent Document 5: WO 95/04809A    Patent Document 6: WO 97/16523A    Patent Document 7: JP-A No. 8-225564    Patent Document 8: JP-A No. 2000-96443    Patent Document 9: JP-A No. 2006-161226    Nonpatent Document 1: Angew. Chem. Int. Ed, 2007, 46, 5836-5863